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John Langille

October 2, 2009

Biomass Characteristics

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Quiz

Biomass does not produce CO2.

Biomass does produce CO2.

Biomass does not make net addition to CO2.

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Outline

Definition of Biomass

Biomass Classification

Classification of Biomass Fuels Properties of Biomass

Physical

Thermodynamic

Other

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What is Biomass?

Any organic material derived from plants

(botanical) or animals (biological)

A non-fossilized fuel source that is

biodegradable

Excludes materials normally used as foods

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A Renewable Energy Source

When biomass dies it is naturally broken

down and releases H2O, CO2, and energy

The same change happens when used for

chemical or energy purposes

Net pollution contribution is zero!

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How is Biomass Formed?

Botanical (plant) biomass converts CO2 andH2O to carbohydrate and oxygen with energy

from the sun through photosynthesis

Biological (animal) species grow by

consuming botanical species or other

biological species

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Biomass Classification

A. Virgin Biomass1. Terrestrial

Forest

Grasses

Energy crops Cultivated crops

2. Aquatic

Algae

Water plants

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Biomass Classification

B. Waste Biomass1. Municipal waste

Municipal solid waste

Bio-solids, sewage

Landfill gas

2. Agricultural solid waste

Livestock and manures

Agricultural crop residues

3. Forestry residues Bark, leaves, floor residues

4. Industrial wastes

Demolition wood, sawdust

Waste oil, fat

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Classification of Biomass Fuels

1. Atomic ratios H:C:O content

van Krevelen diagram (H/C versus O/C)

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Classification of Biomass Fuels

1. Atomic ratios

2. Ratio of biomass components

Cellulose, hemicellulose, and lignin

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Classification of Biomass Fuels

1. Atomic ratios

2. Ratio of biomass components

3. Ternary diagram

Shows biomass conversion processes interms of H:C:O ratio

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Physical Properties of Biomass

True density

true =

total mass of biomass

solid volume in biomass

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Physical Properties of Biomass

True density

Apparent density

apparent =

total mass of biomass

volume of solids and internal pores

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Physical Properties of Biomass

True density

Apparent density

Bulk density

bulk=

total mass of biomass particles or stack

bulk volume occupied by particles or stack

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Physical Properties of Biomass

True density

Apparent density

Bulk density

Biomass density

Biomass available per unit area land

Kg/hectare of a harvested crop

Oven dry tons/hectare of trees

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Thermodynamic Properties of Biomass

Thermal conductivity The ability of the biomass to conduct heat

Specific heat

The amount of heat required to raise a unit

mass of biomass by one unit of a specified

temperature

Heat of formation

Energy to form the biomass from its constituent

elements

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Other Properties of Biomass

Bases of expressing biomass composition As received basis

Ultimate analysis

Determines the composition of the biomass

fuel in terms of basic elements

C + H + O + N + S + A + M = 100%

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Other Properties of Biomass

Bases of expressing biomass composition As received basis

Proximate analysis

Determines the composition of the biomass

fuel in terms of gross components

VM + FC + A + M = 100%

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Other Properties of Biomass

Bases of expressing biomass composition As received basis

Air dry basis

The biomass is dried in air, removing surface moisture

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Other Properties of Biomass

Bases of expressing biomass composition As received basis

Air dry basis

Dry basis

The biomass completely dried, removing both surface

and inherent moisture

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Other Properties of Biomass

Bases of expressing biomass composition As received basis

Air dry basis

Dry basis

Dry and ash free basis

Components are reported with ash and water removed

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